Rifle mounted optical unit

Abstract

A warning unit for attachment to a handheld firearm comprises an attachment device for attachment to a firearm, a light source, and a digitally manipulable input device operable to enable selection of a mode of operation. The warning unit is capable of being operated in at least a narrow divergence mode, and a wide divergence mode wherein, in the narrow divergence mode, the warning unit is operable to emit a beam of light of a lower divergence than in the wide divergence mode.

1. A warning unit for attachment to a handheld firearm, the warning unit comprising:
 attachment means for attachment to a firearm, 
 a light source, 
 expansion optics for expanding a beam of light emitted by the light source, 
 divergence optics for controlling an amount of divergence of the beam emitted by the light source, 
 a controller for controlling the extent to which the expansion optics expand the beam of light and for controlling the extent to which the divergence optics impose a divergence on the beam of light, 
 input means actuatable by a user's hand to enable selection of a mode of operation of the warning unit, the warning unit being capable of being operated in at least a narrow divergence mode, and a wide divergence mode, 
 wherein, 
 in the narrow divergence mode, the controller is operable to cause the expansion optics to reduce the extent to which the beam is expanded and to cause the divergence optics to reduce the extent to which the beam of light diverges, to thereby cause the warning unit to emit a beam of light of a lower divergence than in the wide divergence mode. 
 
     
     
       2. A warning unit in accordance with  claim 1  wherein the light source is a laser light source. 
     
     
       3. A warning unit in accordance with  claim 2  wherein the laser light source is a laser diode. 
     
     
       4. A warning unit in accordance with  claim 1  wherein said light source is operable to emit a beam of light which is substantially green in the visible spectrum. 
     
     
       5. A warning unit in accordance with  claim 1 , wherein said input means comprises at least one push button. 
     
     
       6. A warning unit in accordance with  claim 5  wherein said input means comprises first and second push buttons, for respective modes of operation of the warning unit. 
     
     
       7. A warning unit in accordance with  claim 1  and including a second input means which, when actuated by a user's hand, causes said warning unit to impose a time varying envelope on a beam of light emitted in operation in any of said modes of operation. 
     
     
       8. A warning unit in accordance with  claim 7  wherein said time varying envelope comprises a square wave, thereby causing said beam of light to pulse. 
     
     
       9. A warning unit in accordance with  claim 1  and including intensity control means operable in a torch mode to cause said beam of light to be of lower intensity than in said warning mode.